character storage unit
Technical computing term for a unit of storage used to hold a single character. Rare outside specialized contexts.
In this system, the character storage unit is one byte.
記憶単位 is a broader term for any storage unit, while 文字記憶単位 specifically refers to a unit for storing a character.
Compound of 文字 (character) + 記憶 (storage) + 単位 (unit). A straightforward technical term with no known historical derivation beyond its components.